分别在880℃/10min和880℃/60min规范下,采用Ag-Cu-Ti活性钎料实现了SiO2f/SiO2复合陶瓷与C/C复合材料的真空钎焊连接,通过电子探针(EPMA)、能谱仪(xEDS)和X射线衍射仪(XRD)分析了接头微观组织,室温下测试了接头的抗剪强度。结果表明:两种规范下所得接头界面结合良好,接头中靠近两侧母材均形成了一层扩散反应层,钎缝基体主要由均匀的共晶组织组成。880℃/10min规范下钎焊接头界面产物依次为:SiO2f/SiO2→Ti4O7→Ti5Si4+Cu(s,s)+Ag-Cu共晶合金→TiC→C/C;对于880℃/60min规范下的接头,界面组织结构与保温10min的接头基本类似,但是不存在Cu(s,s),并且接头反应层明显增厚。880℃/60min条件下所得钎焊接头剪切强度平均值为16.6MPa。
SiO2f/SiO2 composite was joined to C/C composite using Ag-Cu-Ti active brazing foils at brazing temperature of 880℃ for 10min and 60min, respectively. The microstructure of joint was analyzed by electron probe micro-analyzer(EPMA),X-ray energy dispersive spectrometer(XEDS) and X- ray diffraction(XRD). Meanwhile, the shear strength of joints was tested at room temperature. The results show that sound joints are achieved and two thin diffusion reaction layers have been formed close to the base materials. The brazing seam matrix is composed of homogeneous eutectic alloy. The typical interface structure of joint brazed at 880℃ for 10min can be described as the following se- quence. SiO2f/SiO2→Ti4O7→Ti5Si4+Gu ( s, s) +Ag-Cu eutectic alloy→TiC→ C/C. The microstructure of the joints brazed at 880℃ for 60min is similar to the former except the absence of Cu(s, s). Furthermore, the reaction layers of joints brazed for 60min are much thicker than those brazed for 10min. The joints brazed at 880℃ for 60rain show an average shear strength of 16.6MPa.